Lathe-dog



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0 E 0. W. LE 001m.

LATHE DOG.

No. 453,761. Patented June 9,1891.

NTTnn STATES PATENT OFFICE.

LATH E-DOG.

SPECIFICATION forming part of Letters Patent No. 453,761, dated June 9, 1891.

Application filed October 6, 1890.

To all whom it may concern.-

Be it known that I, CHARLES W. Lu COUNT, a citizen of the United States, residing at South Norwalk, in the county of Fairtleld and State of Connecticut, have invented certain new and useful Improvements in Lathe- Dogs; and I do hereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to produce a simple, inexpensive, and durable lathe-dog which will grasp an articleas, for instance, a pipe--and hold it perfectly firm, no matter in which direction the strain is applied, slipping being practically impossible when the dog is once tightened up, and the danger of marriug the pipe or other article held being wholly avoided.

\Vith these ends in view I have devised the simple and novel construction which I will now describe, referring by numerals to the accompanying drawings, forming part of this specification, in which Figure 1 is an elevation of my novel device complete; Fig. 2, a similar view illustrating an obvious modification; Fig. 3, a section on the line a; no in Fig. 1, looking down; and Fig. 4 is a section corresponding with the lineyy in Fig. 1, but illustrating a slight change in the details of construction.

1 denotes the body of the chuck, which may be of anysuitable or preferred form, and is provided with a central opening 2 to receive the article to be held.

In practice the pipe or other article is held by three points of contact, the essential principle of my invention being that either one or two of the points of contact consist of rollers 33, which lie in a recess 9 and extend into the central opening. These rollers are provided with suitable journals at, which bear in inclined slots 5, the construction being such that the journals of the roller or rollers will naturally seek the lowest portions of the slots so that when power is applied to turn the tube or other article backward the tend- Serial No. 367,228. (No model.)

eucy will be to force a roller up an incline, which will have the effect of wedging the article, gri-pping itmore firmly. The other contact point or points consist of set-screws 6, extending through the body and into the central opening, which may be operated by hand or by a suitable hand-tool. In my preferred form, as in Fig. 1, I use two rollers and one set-screw. The rollers may be mounted in plates '7 on both sides of the body, as in Figs. 1, 2, and 3, slots 5 being formed in both plates, or a groove 5 may be formed in the body on one side, as in Fig. l, and a similar groove in a plate 7 011 the oppositeside. In this form the grooves are preferably made V-shaped, and the journals are shaped to correspond, so that the journals themselves do not show on the outer side of the body.

In the form shown in Figs. 1, 3, and 4 the rollers are placed at a suitable distance apart to give two of the required hearings to the article to be held, and in the form shown in Fig. 2 the set-screws are placed at a suitable distance apart to give two of the bearings, the roller at its lowest position in this form being on a line midway between the setscrews, and the slots inclining upward in both directions, so that when strain is applied in either direction the tendency will be to force the roller upward, thereby wedging the article held and gripping it still more firmly. The plates are held in position by screws 8, which engage the body and may have countersunk heads, or, if preferred, raised heads, as shown in Fig. 3.

Having thus described my invention, I clain1 1. A lathe-dog having a central opening to receive the article to be held, and bearingpoints consisting of set-screws and rollers mounted in inclined bearings, so that movement of the article in either direction after tightening up will force a roller up an incline, thereby wedging the article and gripping it more firmly.

2. A lathe-dog having a central opening, a set-screw extending into said opening, and rollers mounted in inclined slots, which serve as the other bearings for the article to be and the other a corresponding groove in a held. plate detachably secured to the body. [0 3. A lathe-dog having a central opening, a In testimony whereof Iaffix my signature in set-screw extending into said opening, a represence of two witnesses. 5 cess opposite to the set-screw, and rollers in CHARLES \V. LE COUNT.

said recess extending into the central open- WVit'nesses:

ing, said rollers being provided with journals, GILBERT M. BITCH,

one of which engages a groove in the body DANIEL P. MORRELL.- 

